Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5916628 | Molecular Immunology | 2015 | 8 Pages |
Abstract
Germinal center (GC) B cells undergo apoptosis after B cell receptor (BCR) ligation, unless they receive CD40-mediated survival signal from helper T cells. In the present study, we used a human follicular lymphoma cell line HF1A3, as an in vitro model to study the selection process in germinal centers. We show here that BCR ligation led to immediate ERK1/2 activation and phosphorylations of its downstream targets, Bim EL/L and Bcl-2 (at Ser70) which resulted in short-term survival. On the other hand, during the late phase of BCR signaling, ERK1/2 phosphorylation was inhibited which resulted in apoptosis. In addition, CD40 signaling led to sustained ERK1/2 activation and up-regulation of Bcl-xL in BCR-primed HF1A3 GC B cells. In conclusion, MEK-ERK pathway and Bcl-2 family proteins are crucial players in BCR-mediated survival/apoptosis and CD40-mediated survival.
Related Topics
Life Sciences
Biochemistry, Genetics and Molecular Biology
Molecular Biology
Authors
Jemal Adem, Aleksi Hämäläinen, Antti Ropponen, Jonna Eeva, Mine Eray, Ulla Nuutinen, Jukka Pelkonen,